Ovary pain for the last two years

I've been suffering with pain in my ovaries for the last two years, first it started as a dull ache about a week before I was due to be on my period but over the last few months it's been constant and really quite painful. It's a really deep dull ache, and after intercourse it is extremely painful. I've had numerous internals and ultrasounds so the doctors presumed it was endometriosis. I've recently had a laparoscopy to check for this and they claim they've found nothing. They just told me if the pain carries on to go back to my doctors, which it still is but the doctors seem just as clueless as I am. Its taken a year for me to get that far and It's really quite painful now and i feel like I'm back to square one. Anyone have any ideas?